Ornamental knob and the formation thereof



Patented May 28, 1935,

PATENT OFFICE oRNAMENTAL KNOB ANDl THE FORMATION r Y THEREoF l Y DavdE. Johnson, Rockford, Ill.

, Application November 11, 1932, Serial No. 642,201

3 Claims. This invention `relates to ornamental knobs for use on furniture, Woodwork, and thelike, andhas more particular reference to the formation of a knob having a flange at the base of the knob heads adapted to abut against a Wood or other surface when the knob is tightened into place.

One object of the invention is to provide as a new article of manufacture a screw or knob of the above character forged from a single piece of Wire and having an integral annular collar or flange forming an abutment shoulder at the juncture of a threaded shank and a head having a base portion of larger diameter than said shank.

Another object of the present invention is to provide a novel process of manufacture by which a knob of the above character may be formed from a single piece of wire of uniform cross-section.

In carrying out the foregoing object, the process involves shaping a piece of wire to form an annular shoulder between opposite end portions of different diameters and forming an outwardly projecting ange from the metal of the larger end portion adjacent said shoulder.

The invention also resides in the novel method of forming the head flange from the metal of the shouldered blank. A

Other objects and advantages of the invention will become apparent `from the following detailed description taken in conjunction with the accompanying drawing, in which c Figure lillustrates the different steps involved inthe formation of a knob accordingto the present invention.

Figs.l 2 and 3 are fragmentary sectional views of the dies and work pieces showing their relation flange.

Fig. 4 is an enlarged section view showing a knob `made in accordance with the present invention turned or screw-threaded into a piece of Wood.

',Figs. 5, 6 and V'7 are views similar to Figs. 2, 3 and 4 illustrating the manner of manufacture and use of a knob having a different type of shank.

Referring first to the Figs. 1 to 4,' the knob illustrated therein comprises ahead 8 having an end of any desired ornamental shape and a base 9 which preferably tapers rather sharply adjacent the head and then more gradually' to a substantially uniform diameter near its end which merges along a curved surface I into an annular flange I I. The latter preferably has a curved outer peripheral edge I2 and its diameter is proportioned relative to the head to` give the desired artistic appearance. The surface I3 of flange II opposite the head is usually disposed vat right angles tothe axis of the knob and thus is adapted to abut against the face of the Wood piece I4 to which the knob is applied by screwing a threaded shank I5 into the wood. l

The process contemplated by the present in- 5 vention involves the use of work-blanks I5 formed by cutting successive predetermined lengths from a Wire of stock of the proper uniform diameter. The blanks are then operated upon in a heading machine of well known construction, one end of the blank being upset in one or more operations and then forged into the desired shape with the base 9 thereof preferably tapering to a substantially uniform diameter at its end. In the headforming operation or in a different forging operation, a shoulder VI'I is formed intermediate the ends of the'blank with its outer peripheral edge merging with the base 9 and its inner edge mergi ing intoV a shank I8 of uniform diameter and somewhat shorter in length than the screwthreaded shank I5 eventually to be formed. In order to give the desired curvature to the outer edge of the flange Il, as will later appear, the surface of shoulder I1 preferably is beveled and tapers toward the shank I8.

' In the present instance, the flange I I is formed byshearing back the metal of the base 9 beginning at the shoulder II while the base or headvis unsupported laterally. To position the shouldered blank accurately for this operation, the blank is supported through the medium of its shank I8 which is suitable for this purpose. The blank is. thenprojected into one end of a bore I9 of a. diameter slightly greater than the shank and thus adapted to snugly receive the latter. The bore I9 is in a die 20 having a flat face dening a cutting edge at the open end of the bore. With the blank thus firmly supported, it is forced into the bore` a predetermined distance beyond the shoulder I'I which may be accomplished by relative axial approaching movement between the die 20 and a plunger or block 2| having a socket 22 shaped to receive the end of the head 8 In this movement, the-metal at the end of the base 9 is sheared back as shown in Fig. 3 along the diameter of the shank I8 beginning at the shoulder Il, the cutting edge of the die at the open end of the bore I 9 serving to eiect the desired shearing action. The metal thus removed from the outer peripheral portion of the base `9 at the end thereof spreads outwardly as the blocks 20 and 2| move toward each other thereby forming the flange II. VUpon separation ofthe blocks, the Work-piece is ejected in the usual way by projecting a pin 22a through the bore i9 into abutment with the end of the shank i8.

The radial width of the flange l l is determined by the extent to which the base S is forced into the die. It has been found that a flange of substantially radial width may be formed without danger of cracks being formed at the outer pcripheral edge of the flange H. The shearing operation, it will be observed, occurs without any external lateral support for the head E and its base 9. Notwithstanding this,l the base 9 is not disgured and the flange is formed with the graceful curve lil adjacent the end of the base The curve if which is desirable from the standpoint of artistic appearance is due in part to the 'beveled character of the shoulder i?.

By avoiding the provision of lateral support for the base 9 during the shearingoperation, it will be apparent that this operation is greatly simplified and the cost of the equipment required reduced to a minimum. This is made possible by supporting` the, shouldered blank through the medium of theel-rank id during the shearing operation. With method of support during shearing, the blank'is held firmly and accurately in centered position relative to the cutting edge of the die insuring the formation of a flange of uniform radial width.

l The surface of the flange i l on the side opposite the head 8 will be shaped according to the contour of the face of the die 2E) and the major portion of this surface will ordinarily be disposed in a plane perpendicular to the shank I8. When the knob is to be screwed into wood as shown in Fig. ll, it is preferred to shape the outer surface adjacent the shank in which recess the cuttings 2li formed Yas the knob is screwed into the wood may accumulate thereby permitting the flange to be drawn tightly and squarely against the face of the board. The recess 23 may, if desired, be formedv in the dangeforming operation above described, To this end, a narrow annular ridge 25' formed on the face of the die 2Q at the end of the bore I9.

In the shearing operation, the metal flows around this ridge having the recess 23 in the iiange,v the outer surface i3 of the ange beingY perpendicular to the knob axis.

After formation of the flange ll, the shank I8' is threaded by the use' of well-known screwthreading machinery. After cutting of the lastV thread adjacent the flange il, the threading tool is allowed to dwell adjacent the ange so as to form an annular groove 25 communicating with the under cut recess 23 and affording additional spacein which the wood-cuttings may accumulate.

For certain applications, the knob is secured to the board by a screw 2l projecting through the board from the opposite side thereof and threading into the shank i8. knobs the shank is not threaded externally but is tapped to form a borewhich is later threaded to receive the screw 2l. The method of forming the flange on knobs of this latter character is in the case of such generally similar to the method first described as will be seen from Figs. 5 and 6, a somewhat shorter but larger shank I8 being formed by varying the size of the bore i9 and the extent of relative movement between the dies 2U and 2l. For this type of knob, the die 2E! would be formed with a flat face forming a correspondingly shaped perpendicular surface I3 on the flange Il.

With the'process above described, it will be apparent'that an ornamental knob having a flanged base may be forged from an integral piece of wire of uniform diameter with a minimum number of operations. The process lends itself to high speed production with minimum equipment and labor costs and makes possible the formation of knobs of more rugged character and more artistic appearance than those now in service use.

I claim as my invention:

vl. For forming a knob having an ornamental head and a shank at opposite ends with an annular ornamental flange projecting radially from the base of said head, the process which comprises forging a piece of wirel to form said head at one end of the wire, a circular shoulder at the base of and facing away from said head and an vend portion of uniform cross-section, projecting the end portion into a die recess snugly receiving the same' and forcing the wire into the die without lateral support for the base of the head whereby to lengthen said shank and shear back the metal at the base of said-head so that the natural ow of the metal forms an annular flange at the juncture of said shank and the base of said head.

2. For forming a one-piece screw knob having anenlarge'd head and a threaded shank at opposite ends with an annular flange providing a radially disposed abutment shoulder at the base of saidl head, the process which comprises forging one end ofa piece of wire to form an enlarged head with a oase extending therefrom and terminatingat an annular shoulder of smaller diameter, the other end portion of the wire forming a shank of uniform diameter less than said base and merging with said shoulder, projecting said end portion into a continuous annular die hole receiving such end and supporting the wire, applying an end rthrust to the end of saidhead to cause the die to shear back the metal of said shank and thereby form said flange, and thereafter threading'said shank.

3. As a new article of manufacture, a screw knob formed from a wire blank and comprising j an enlarged head forged at one end of the wire,

v an intermediate portion of smaller diameter than the head, a threaded stem of smaller diameter than the intermediate portion, andanV integral radial collar at the junction of the intermediate portion and the stem, said collar adapted to be formed by shearing back the metal of part of the cylindrical portion to produce the Vcollar and p roviding a shoulder abutment facing said stem.

' DAVID E; JOHNSON. 

